Journal articles on the topic 'Non-methane volatile organic compounds (NMVOCs)'
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1
Lanz, V. A., S. Henne, J. Staehelin, C. Hueglin, M. K. Vollmer, M. Steinbacher, B. Buchmann, and S. Reimann. "Statistical analysis of anthropogenic non-methane VOC variability at a European background location (Jungfraujoch, Switzerland)." Atmospheric Chemistry and Physics 9, no. 10 (May 28, 2009): 3445–59. http://dx.doi.org/10.5194/acp-9-3445-2009.
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Abstract. In-situ measurements of 7 volatile hydrocarbons, CxHy, and 3 chlorinated organic compounds, CxHyClz, were performed at Jungfraujoch (Switzerland) during eight years (2000–2007). The analysis of 4-h resolved non-methane volatile organic compounds (NMVOCs) was achieved by using gas-chromatography coupled with mass spectrometry (GC-MS). Variabilities in the NMVOC time series dataset were modeled by factor analysis (positive matrix factorization, PMF). Four factors defined the solution space and could be related to NMVOC sources and atmospheric processes. In order to facilitate factor interpretations the retrieved contributions were compared with independent measurements, such as trace gases (NOx, CO, and CH4) and back trajectories. The most dominant factor (accounting on average for ~42% of the total mixing ratio of the considered NMVOCs) was found to be most active in winter, co-varying with CO and CH4 and could be related to aged combustive emissions as well as natural gas distribution. The other three factors represent both industrial and evaporative sources. Trajectory statistics suggest that the most influential anthropogenic NMVOC sources for Jungfraujoch are located in Eastern Europe, but the Po Valley has been identified as a potential source region for specific industrial sources as well. Aging of the arriving NMVOCs, the derived factors as well as limitations of the methods are discussed. This is the first report of a PMF application on NMVOC data from a background mountain site.
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Fry, M. M., M. D. Schwarzkopf, Z. Adelman, and J. J. West. "Air quality and radiative forcing impacts of anthropogenic volatile organic compound emissions from ten world regions." Atmospheric Chemistry and Physics 14, no. 2 (January 16, 2014): 523–35. http://dx.doi.org/10.5194/acp-14-523-2014.
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Abstract. Non-methane volatile organic compounds (NMVOCs) influence air quality and global climate change through their effects on secondary air pollutants and climate forcers. Here we simulate the air quality and radiative forcing (RF) impacts of changes in ozone, methane, and sulfate from halving anthropogenic NMVOC emissions globally and from 10 regions individually, using a global chemical transport model and a standalone radiative transfer model. Halving global NMVOC emissions decreases global annual average tropospheric methane and ozone by 36.6 ppbv and 3.3 Tg, respectively, and surface ozone by 0.67 ppbv. All regional reductions slow the production of peroxyacetyl nitrate (PAN), resulting in regional to intercontinental PAN decreases and regional NOx increases. These NOx increases drive tropospheric ozone increases nearby or downwind of source regions in the Southern Hemisphere (South America, Southeast Asia, Africa, and Australia). Some regions' NMVOC emissions contribute importantly to air pollution in other regions, such as East Asia, the Middle East, and Europe, whose impact on US surface ozone is 43%, 34%, and 34% of North America's impact. Global and regional NMVOC reductions produce widespread negative net RFs (cooling) across both hemispheres from tropospheric ozone and methane decreases, and regional warming and cooling from changes in tropospheric ozone and sulfate (via several oxidation pathways). The 100 yr and 20 yr global warming potentials (GWP100, GWP20) are 2.36 and 5.83 for the global reduction, and 0.079 to 6.05 and −1.13 to 18.9 among the 10 regions. The NMVOC RF and GWP estimates are generally lower than previously modeled estimates, due to the greater NMVOC/NOx emissions ratios simulated, which result in less sensitivity to NMVOC emissions changes and smaller global O3 burden responses, in addition to differences in the representation of NMVOCs and oxidation chemistry among models. Accounting for a fuller set of RF contributions may change the relative magnitude of each region's impacts. The large variability in the RF and GWP of NMVOCs among regions suggest that regionally specific metrics may be necessary to include NMVOCs in multi-gas climate trading schemes.
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Fry, M. M., M. D. Schwarzkopf, Z. Adelman, and J. J. West. "Air quality and radiative forcing impacts of anthropogenic volatile organic compound emissions from ten world regions." Atmospheric Chemistry and Physics Discussions 13, no. 8 (August 13, 2013): 21125–57. http://dx.doi.org/10.5194/acpd-13-21125-2013.
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Abstract. Non-methane volatile organic compounds (NMVOCs) influence air quality and global climate change through their effects on secondary air pollutants and climate forcers. Here we simulate the air quality and radiative forcing (RF) impacts of changes in ozone, methane, and sulfate from halving anthropogenic NMVOC emissions globally and from 10 regions individually, using a global chemical transport model and a standalone radiative transfer model. Halving global NMVOC emissions decreases global annual average tropospheric methane and ozone by 36.6 ppbv and 3.3 Tg, respectively, and surface ozone by 0.67 ppbv. All regional reductions slow the production of PAN, resulting in regional to intercontinental PAN decreases and regional NOx increases. These NOx increases drive tropospheric ozone increases nearby or downwind of source regions in the Southern Hemisphere (South America, Southeast Asia, Africa, and Australia). Some regions' NMVOC emissions contribute importantly to air pollution in other regions, such as East Asia, Middle East, and Europe, whose impact on US surface ozone is 43%, 34%, and 34% of North America's impact. Global and regional NMVOC reductions produce widespread negative net RFs (cooling) across both hemispheres from tropospheric ozone and methane decreases, and regional warming and cooling from changes in tropospheric ozone and sulfate (via several oxidation pathways). The total global net RF for NMVOCs is estimated as 0.0277 W m−2 (~1.8% of CO2 RF since the preindustrial). The 100 yr and 20 yr global warming potentials (GWP100, GWP20) are 2.36 and 5.83 for the global reduction, and 0.079 to 6.05 and −1.13 to 18.9 among the 10 regions. The NMVOC RF and GWP estimates are generally lower than previously modeled estimates, due to differences among models in ozone, methane, and sulfate sensitivities, and the climate forcings included in each estimate. Accounting for a~fuller set of RF contributions may change the relative magnitude of each region's impacts. The large variability in the RF and GWP of NMVOCs among regions suggest that regionally-specific metrics may be necessary to include NMVOCs in multi-gas climate trading schemes.
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Huang, Ganlin, Rosie Brook, Monica Crippa, Greet Janssens-Maenhout, Christian Schieberle, Chris Dore, Diego Guizzardi, Marilena Muntean, Edwin Schaaf, and Rainer Friedrich. "Speciation of anthropogenic emissions of non-methane volatile organic compounds: a global gridded data set for 1970–2012." Atmospheric Chemistry and Physics 17, no. 12 (June 26, 2017): 7683–701. http://dx.doi.org/10.5194/acp-17-7683-2017.
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Abstract. Non-methane volatile organic compounds (NMVOCs) include a large number of chemical species which differ significantly in their chemical characteristics and thus in their impacts on ozone and secondary organic aerosol formation. It is important that chemical transport models (CTMs) simulate the chemical transformation of the different NMVOC species in the troposphere consistently. In most emission inventories, however, only total NMVOC emissions are reported, which need to be decomposed into classes to fit the requirements of CTMs. For instance, the Emissions Database for Global Atmospheric Research (EDGAR) provides spatially resolved global anthropogenic emissions of total NMVOCs. In this study the EDGAR NMVOC inventory was revised and extended in time and in sectors. Moreover the new version of NMVOC emission data in the EDGAR database were disaggregated on a detailed sector resolution to individual species or species groups, thus enhancing the usability of the NMVOC emission data by the modelling community. Region- and source-specific speciation profiles of NMVOC species or species groups are compiled and mapped to EDGAR processes (detailed resolution of sectors), with corresponding quality codes specifying the quality of the mapping. Individual NMVOC species in different profiles are aggregated to 25 species groups, in line with the common classification of the Global Emissions Initiative (GEIA). Global annual grid maps with a resolution of 0.1° × 0.1° for the period 1970–2012 are produced by sector and species. Furthermore, trends in NMVOC composition are analysed, taking road transport and residential sources in Germany and the United Kingdom (UK) as examples.
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Stewart, Gareth J., W. Joe F. Acton, Beth S. Nelson, Adam R. Vaughan, James R. Hopkins, Rahul Arya, Arnab Mondal, et al. "Emissions of non-methane volatile organic compounds from combustion of domestic fuels in Delhi, India." Atmospheric Chemistry and Physics 21, no. 4 (February 18, 2021): 2383–406. http://dx.doi.org/10.5194/acp-21-2383-2021.
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Abstract. Twenty-nine different fuel types used in residential dwellings in northern India were collected from across Delhi (76 samples in total). Emission factors of a wide range of non-methane volatile organic compounds (NMVOCs) (192 compounds in total) were measured during controlled burning experiments using dual-channel gas chromatography with flame ionisation detection (DC-GC-FID), two-dimensional gas chromatography (GC × GC-FID), proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) and solid-phase extraction two-dimensional gas chromatography with time-of-flight mass spectrometry (SPE-GC × GC–ToF-MS). On average, 94 % speciation of total measured NMVOC emissions was achieved across all fuel types. The largest contributors to emissions from most fuel types were small non-aromatic oxygenated species, phenolics and furanics. The emission factors (in g kg−1) for total gas-phase NMVOCs were fuelwood (18.7, 4.3–96.7), cow dung cake (62.0, 35.3–83.0), crop residue (37.9, 8.9–73.8), charcoal (5.4, 2.4–7.9), sawdust (72.4, 28.6–115.5), municipal solid waste (87.3, 56.6–119.1) and liquefied petroleum gas (5.7, 1.9–9.8). The emission factors measured in this study allow for better characterisation, evaluation and understanding of the air quality impacts of residential solid-fuel combustion in India.
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Sebos, I., and L. E. Kallinikos. "Modelling of NMVOC emissions from solvents use in Greece." IOP Conference Series: Earth and Environmental Science 1123, no. 1 (December 1, 2022): 012072. http://dx.doi.org/10.1088/1755-1315/1123/1/012072.
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Abstract The use of solvents and other volatile organic chemicals is a significant source of Non-Methane Volatile Organic Compounds (NMVOCs) emissions. Due to the wide spectrum of applications of solvents and numerous locations where these occur, the estimation of NMVOCs emissions can be challenging. The aim of this paper is to present the methodological framework used in Greece for the estimation of NMVOCs emissions. It covers processes and products that use solvents and other volatile organic chemicals in several industries, as well as in households. The framework is based both on existing methods found in the literature and on new emission factors developed in order to reflect the mitigation potential of EU Directives and national legislation aiming at the reduction of NMVOCs emissions. The developed framework was verified by comparing it with solvent emission estimates from the European Solvent Industry Group.
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Sebos, Ioannis, and Leonidas Kallinikos. "NMVOC Emissions from Solvents Use in Greece: Monitoring and Assessment." Atmosphere 14, no. 1 (December 23, 2022): 24. http://dx.doi.org/10.3390/atmos14010024.
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The use of solvents and other volatile organic chemicals is a significant source of Non-Methane Volatile Organic Compounds (NMVOCs) emissions. Due to the wide spectrum of applications of solvents and numerous locations where these occur, the estimation of NMVOCs emissions can be challenging. The aim of this paper is to present the methodological framework used in Greece for the estimation of NMVOCs emissions. It covers processes and products that use solvents and other volatile organic chemicals in several industries, as well as in households. The framework is based both on existing methods found in the literature and on new emission factors developed in order to reflect the mitigation potential of EU Directives and national legislation aiming at the reduction of NMVOCs emissions. The developed framework was used to forecast future NMVOCs emissions and assess the implemented mitigation actions. Results were verified by comparison with solvent emission estimates from the European Solvent Industry Group.
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Mo, Ziwei, Ru Cui, Bin Yuan, Huihua Cai, Brian C. McDonald, Meng Li, Junyu Zheng, and Min Shao. "A mass-balance-based emission inventory of non-methane volatile organic compounds (NMVOCs) for solvent use in China." Atmospheric Chemistry and Physics 21, no. 17 (September 14, 2021): 13655–66. http://dx.doi.org/10.5194/acp-21-13655-2021.
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Abstract. Non-methane volatile organic compounds (NMVOCs) are important precursors of ozone (O3) and secondary organic aerosol (SOA), which play key roles in tropospheric chemistry. A huge amount of NMVOC emissions from solvent use are complicated by a wide spectrum of sources and species. This work presents a long-term NMVOC emission inventory of solvent use during 2000–2017 in China. Based on a mass (material) balance method, NMVOC emissions were estimated for six categories, including coatings, adhesives, inks, pesticides, cleaners, and personal care products. The results show that NMVOC emissions from solvent use in China increased rapidly from 2000 to 2014 then kept stable after 2014. The total emission increased from 1.6 Tg (1.2–2.2 Tg at 95 % confidence interval) in 2000 to 10.6 Tg (7.7–14.9 Tg) in 2017. The substantial growth is driven by the large demand for solvent products in both industrial and residential activities. However, increasing treatment facilities in the solvent-related factories in China restrained the continued growth of solvent NMVOC emissions in recent years. Rapidly developing and heavily industrialized provinces such as Jiangsu, Shandong, and Guangdong contributed significantly to the solvent use emissions. Oxygenated VOCs, alkanes, and aromatics were the main components, accounting for 42 %, 28 %, and 21 % of total NMVOC emissions in 2017, respectively. Our results and previous inventories are generally comparable within the estimation uncertainties (−27 %–52 %). However, there exist significant differences in the estimates of sub-categories. Personal care products were a significant and quickly rising source of NMVOCs, which were probably underestimated in previous inventories. Emissions from solvent use were growing faster compared with transportation and combustion emissions, which were relatively better controlled in China. Environmentally friendly products can reduce the NMVOC emissions from solvent use. Supposing all solvent-based products were substituted with water-based products, it would result in 37 %, 41 %, and 38 % reduction of emissions, ozone formation potential (OFP), and secondary organic aerosol formation potential (SOAP), respectively. These results indicate there is still large potential for NMVOC reduction by reducing the utilization of solvent-based products and implementation of end-of-pipe controls across industrial sectors.
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Pecorini, Isabella, Elena Rossi, and Renato Iannelli. "Mitigation of Methane, NMVOCs and Odor Emissions in Active and Passive Biofiltration Systems at Municipal Solid Waste Landfills." Sustainability 12, no. 8 (April 15, 2020): 3203. http://dx.doi.org/10.3390/su12083203.
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Biofiltration systems are emerging technological solutions for the removal of methane and odors from landfill gas when flaring is no longer feasible. This work analyzed and compared two full-scale biofiltration systems: biofilter and biowindows. The emission mitigation of methane, non-methane volatile organic compounds (NMVOCs) and odors during a two-year management and monitoring period was studied. In addition to diluted methane, more than 50 NMVOCs have been detected in the inlet raw landfill gas and the sulfur compounds resulted in the highest odor activity value. Both systems, biofilter and biowindows, were effective for the oxidation of methane (58.1% and 88.05%, respectively), for the mitigation of NMVOCs (higher than 80%) and odor reduction (99.84% and 93.82% respectively). As for the biofilter monitoring, it was possible to define the oxidation efficiency trend and in fact to guarantee that for an oxidation efficiency of 80%, the methane load must be less than 6.5 g CH4/m2h with an oxidation rate of 5.2 g CH4/m2h.
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An, Jingyu, Yiwei Huang, Cheng Huang, Xin Wang, Rusha Yan, Qian Wang, Hongli Wang, et al. "Emission inventory of air pollutants and chemical speciation for specific anthropogenic sources based on local measurements in the Yangtze River Delta region, China." Atmospheric Chemistry and Physics 21, no. 3 (February 10, 2021): 2003–25. http://dx.doi.org/10.5194/acp-21-2003-2021.
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Abstract. A high-resolution air pollutant emission inventory for the Yangtze River Delta (YRD) region was updated for 2017 using emission factors and chemical speciation based mainly on local measurements in this study. The inventory included 424 non-methane volatile organic compounds (NMVOCs) and 43 fine particulate matter (PM2.5) species from 259 specific sources. The total emissions of SO2, NOx, CO, NMVOCs, PM10, PM2.5, and NH3 in the YRD region in 2017 were 1552, 3235, 38 507, 4875, 3770, 1597, and 2467 Gg, respectively. SO2 and CO emissions were mainly from boilers, accounting for 49 % and 73 % of the total. Mobile sources dominated NOx emissions, contributing 57 % of the total. NMVOC emissions, mainly from industrial sources, made up 61 % of the total. Dust sources accounted for 55 % and 28 % of PM10 and PM2.5 emissions, respectively. Agricultural sources accounted for 91 % of NH3 emissions. Major PM2.5 species were OC, Ca, Si, PSO4, and EC, accounting for 9.0 %, 7.0 %, 6.4 %, 4.6 %, and 4.3 % of total PM2.5 emissions, respectively. The main species of NMVOCs were aromatic hydrocarbons, making up 25.3 % of the total. Oxygenated volatile organic compounds (OVOCs) contributed 21.9 % of the total NMVOC emissions. Toluene had the highest comprehensive contribution to ozone (O3) and secondary organic aerosol (SOA) formation potentials, while other NMVOCs included 1,2,4-trimethylbenzene, m,p-xylene, propylene, ethene, o-xylene, and ethylbenzene. Industrial process and solvent-use sources were the main sources of O3 and SOA formation potential, followed by motor vehicles. Among industrial sources, chemical manufacturing, rubber and plastic manufacturing, appliance manufacturing, and textiles made significant contributions. This emission inventory should provide scientific guidance for future control of air pollutants in the YRD region of China.
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Inomata, S., H. Tanimoto, S. Kato, J. Suthawaree, Y. Kanaya, P. Pochanart, Y. Liu, and Z. Wang. "PTR-MS measurements of non-methane volatile organic compounds during an intensive field campaign at the summit of Mount Tai, China, in June 2006." Atmospheric Chemistry and Physics 10, no. 15 (August 3, 2010): 7085–99. http://dx.doi.org/10.5194/acp-10-7085-2010.
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Abstract. Owing to recent industrialization, Central East China has become a significant source of air pollutants. To examine the processes controlling the chemistry and transport of tropospheric ozone, we performed on-line measurements of non-methane volatile organic compounds (NMVOCs) as part of an intensive field campaign at Mount Tai, China, in June 2006 (MTX2006), using proton transfer reaction mass spectrometry (PTR-MS). Temporal variations of NMVOCs were recorded in mass-scan mode from m/z17 to m/z 300 during 12–30 June 2006. More than thirty kinds of NMVOCs were detected up to m/z 160, including alkenes, aromatics, alcohols, aldehydes, and ketones. In combination with non-methane hydrocarbon data obtained by a gas chromatography with flame ionization detection, it was found that oxygenated VOCs were the predominant NMVOCs. Diurnal variations depending mainly on local photochemistry were observed during 24–28 June. During the night of 12 June, we observed an episode of high NMVOCs concentrations attributed to the burning of agricultural biomass. The ΔNMVOCs/ΔCO ratios derived by PTR-MS measurements for this episode (with biomass burning (BB) plume) and during 16–23 June (without BB plume) are compared to emission ratios from various types of biomass burning as reviewed by Andreae and Merlet (2001) and to ratios recently measured by PTR-MS in tropical forests (Karl et al., 2007) and at urban sites (Warneke et al., 2007).
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Inomata, S., H. Tanimoto, S. Kato, J. Suthawaree, Y. Kanaya, P. Pochanart, Y. Liu, and Z. Wang. "PTR-MS measurements of non-methane volatile organic compounds during an intensive field campaign at the summit of Mount Tai, China, in June 2006." Atmospheric Chemistry and Physics Discussions 9, no. 6 (December 11, 2009): 26697–734. http://dx.doi.org/10.5194/acpd-9-26697-2009.
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Abstract. Owing to recent industrialization, Central East China has become a significant source of air pollutants. To examine the processes controlling the chemistry and transport of tropospheric ozone, we continuously measured non-methane volatile organic compounds (NMVOCs) as part of an intensive field campaign at Mount Tai, China, in June 2006 (MTX2006), using proton transfer reaction mass spectrometry (PTR-MS). Temporal variations of NMVOCs were recorded in mass-scan mode from m/z 17 to m/z 300 during 12–30 June 2006. More than thirty kinds of NMVOCs were detected up to m/z 160, including alkenes, aromatics, alcohols, aldehydes, and ketones. Oxygenated VOCs were the predominant NMVOCs. During the night of 12 June, we observed an episode of high NMVOCs concentrations attributed to the burning of agricultural biomass. The ΔNMVOCs/ΔCO ratios derived by PTR-MS measurements for this episode are compared to emission ratios from various types of biomass burning as reviewed by Andreae and Merlet (2001) and to ratios recently measured by PTR-MS in tropical forests (Karl et al., 2007) and at urban sites (Warneke et al., 2007).
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Zhao, Yu, Pan Mao, Yaduan Zhou, Yang Yang, Jie Zhang, Shekou Wang, Yanping Dong, Fangjian Xie, Yiyong Yu, and Wenqing Li. "Improved provincial emission inventory and speciation profiles of anthropogenic non-methane volatile organic compounds: a case study for Jiangsu, China." Atmospheric Chemistry and Physics 17, no. 12 (June 28, 2017): 7733–56. http://dx.doi.org/10.5194/acp-17-7733-2017.
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Abstract. Non-methane volatile organic compounds (NMVOCs) are the key precursors of ozone (O3) and secondary organic aerosol (SOA) formation. Accurate estimation of their emissions plays a crucial role in air quality simulation and policy making. We developed a high-resolution anthropogenic NMVOC emission inventory for Jiangsu in eastern China from 2005 to 2014, based on detailed information of individual local sources and field measurements of source profiles of the chemical industry. A total of 56 NMVOCs samples were collected in nine chemical plants and were then analyzed with a gas chromatography – mass spectrometry system (GC-MS). Source profiles of stack emissions from synthetic rubber, acetate fiber, polyether, vinyl acetate and ethylene production, and those of fugitive emissions from ethylene, butanol and octanol, propylene epoxide, polyethylene and glycol production were obtained. Various manufacturing technologies and raw materials led to discrepancies in source profiles between our domestic field tests and foreign results for synthetic rubber and ethylene production. The provincial NMVOC emissions were calculated to increase from 1774 Gg in 2005 to 2507 Gg in 2014, and relatively large emission densities were found in cities along the Yangtze River with developed economies and industries. The estimates were larger than those from most other available inventories, due mainly to the complete inclusion of emission sources and to the elevated activity levels from plant-by-plant investigation in this work. Industrial processes and solvent use were the largest contributing sectors, and their emissions were estimated to increase, respectively, from 461 to 958 and from 38 to 966 Gg. Alkanes, aromatics and oxygenated VOCs (OVOCs) were the most important species, accounting for 25.9–29.9, 20.8–23.2 and 18.2–21.0 % to annual total emissions, respectively. Quantified with a Monte Carlo simulation, the uncertainties of annual NMVOC emissions vary slightly through the years, and the result for 2014 was −41 to +93 %, expressed as 95 % confidence intervals (CI). Reduced uncertainty was achieved compared to previous national and regional inventories, attributed partly to the detailed classification of emission sources and to the use of information at plant level in this work. Discrepancies in emission estimation were explored for the chemical and refinery sectors with various data sources and methods. Compared with the Multi-resolution Emission Inventory for China (MEIC), the spatial distribution of emissions in this work were more influenced by the locations of large point sources, and smaller emissions were found in urban area for developed cities in southern Jiangsu. In addition, discrepancies were found between this work and MEIC in the speciation of NMVOC emissions under the atmospheric chemistry mechanisms CB05 and SAPRC99. The difference in species OLE1 resulted mainly from the updated source profile of building paint use and the differences in other species from the varied sector contributions to emissions in the two inventories. The Community Multi-scale Air Quality (CMAQ) model simulation was applied to evaluate the two inventories, and better performance (indicated by daily 1 h maximum O3 concentrations in Nanjing) were found for January, April and October 2012 when the provincial inventory was used.
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von Schneidemesser, Erika, Boris Bonn, Tim M. Butler, Christian Ehlers, Holger Gerwig, Hannele Hakola, Heidi Hellén, et al. "BAERLIN2014 – stationary measurements and source apportionment at an urban background station in Berlin, Germany." Atmospheric Chemistry and Physics 18, no. 12 (June 20, 2018): 8621–45. http://dx.doi.org/10.5194/acp-18-8621-2018.
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Abstract. The “Berlin Air quality and Ecosystem Research: Local and long-range Impact of anthropogenic and Natural hydrocarbons” (BAERLIN2014) campaign was conducted during the 3 summer months (June–August) of 2014. During this measurement campaign, both stationary and mobile measurements were undertaken to address complementary aims. This paper provides an overview of the stationary measurements and results that were focused on characterization of gaseous and particulate pollution, including source attribution, in the Berlin–Potsdam area, and quantification of the role of natural sources in determining levels of ozone and related gaseous pollutants. Results show that biogenic contributions to ozone and particulate matter are substantial. One indicator for ozone formation, the OH reactivity, showed a 31 % (0.82 ± 0.44 s−1) and 75 % (3.7 ± 0.90 s−1) contribution from biogenic non-methane volatile organic compounds (NMVOCs) for urban background (2.6 ± 0.68 s−1) and urban park (4.9 ± 1.0 s−1) location, respectively, emphasizing the importance of such locations as sources of biogenic NMVOCs in urban areas. A comparison to NMVOC measurements made in Berlin approximately 20 years earlier generally show lower levels today for anthropogenic NMVOCs. A substantial contribution of secondary organic and inorganic aerosol to PM10 concentrations was quantified. In addition to secondary aerosols, source apportionment analysis of the organic carbon fraction identified the contribution of biogenic (plant-based) particulate matter, as well as primary contributions from vehicles, with a larger contribution from diesel compared to gasoline vehicles, as well as a relatively small contribution from wood burning, linked to measured levoglucosan.
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Dunlop, Mark, Zoran D. Ristovski, Erin Gallagher, Gavin Parcsi, Robin L. Modini, Victoria Agranovski, and Richard M. Stuetz. "Odour, dust and non-methane volatile organic-compound emissions from tunnel-ventilated layer-chicken sheds: a case study of two farms." Animal Production Science 53, no. 12 (2013): 1309. http://dx.doi.org/10.1071/an12343.
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An observational study was undertaken to measure odour and dust (PM10 and PM2.5) emission rates and identify non-methane volatile organic compounds (NMVOCs) and odorants in the exhaust air from two tunnel-ventilated layer-chicken sheds that were configured with multi-tiered cages and manure belts. The study sites were located in south-eastern Queensland and the West Gippsland region of Victoria, Australia. Samples were collected in summer and winter on sequential days across the manure-belt cleaning cycle. Odour emissions ranged from 58 to 512 ou/s per 1000 birds (0.03–0.27 ou/s.kg) and dust emission rates ranged 0.014–0.184 mg/s per 1000 birds for PM10 and 0.001–0.190 mg/s per 1000 birds for PM2.5. Twenty NMVOCs were identified, including three that were also identified as odorants using thermal desorption–gas chromatography–mass spectrometry/olfactometry analysis. Odour emission rates were observed to vary with the amount of manure accumulation on the manure belts, being lowest 2–4 days after removing manure. Odour emission rates were also observed to vary with diurnal and seasonal changes in ventilation rate. Dust emissions were observed to increase with ventilation rate but not with manure accumulation. Some NMVOCs were identified at both farms and in different seasons whereas others were observed only at one farm or in one season, indicating that odorant composition was influenced by farm-specific practices and season.
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Fischer, E. V., D. J. Jacob, R. M. Yantosca, M. P. Sulprizio, D. B. Millet, J. Mao, F. Paulot, et al. "Atmospheric peroxyacetyl nitrate (PAN): a global budget and source attribution." Atmospheric Chemistry and Physics Discussions 13, no. 10 (October 15, 2013): 26841–91. http://dx.doi.org/10.5194/acpd-13-26841-2013.
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Abstract. Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane volatile organic compounds (NMVOCs), is the principal tropospheric reservoir for nitrogen oxide radicals (NOx = NO + NO2). PAN enables the transport and release of NOx to the remote troposphere with major implications for the global distributions of ozone and OH, the main tropospheric oxidants. Simulation of PAN is a challenge for global models because of the dependence of PAN on vertical transport as well as complex and uncertain NMVOC sources and chemistry. Here we use an improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that it can simulate PAN observations from aircraft campaigns worldwide. The immediate carbonyl precursors for PAN formation include acetaldehyde (44% of the global source), methylglyoxal (30%), acetone (7%), and a suite of other isoprene and terpene oxidation products (19%). A diversity of NMVOC emissions is responsible for PAN formation globally including isoprene (37%) and alkanes (14%). Anthropogenic sources are dominant in the extratropical Northern Hemisphere outside the growing season. Open fires appear to play little role except at high northern latitudes in spring, although results are very sensitive to plume chemistry and plume rise. Lightning NOx is the dominant contributor to the observed PAN maximum in the free troposphere over the South Atlantic.
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Fischer, E. V., D. J. Jacob, R. M. Yantosca, M. P. Sulprizio, D. B. Millet, J. Mao, F. Paulot, et al. "Atmospheric peroxyacetyl nitrate (PAN): a global budget and source attribution." Atmospheric Chemistry and Physics 14, no. 5 (March 14, 2014): 2679–98. http://dx.doi.org/10.5194/acp-14-2679-2014.
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Abstract. Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane volatile organic compounds (NMVOCs) is the principal tropospheric reservoir for nitrogen oxide radicals (NOx = NO + NO2). PAN enables the transport and release of NOx to the remote troposphere with major implications for the global distributions of ozone and OH, the main tropospheric oxidants. Simulation of PAN is a challenge for global models because of the dependence of PAN on vertical transport as well as complex and uncertain NMVOC sources and chemistry. Here we use an improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that it can simulate PAN observations from aircraft campaigns worldwide. The immediate carbonyl precursors for PAN formation include acetaldehyde (44% of the global source), methylglyoxal (30%), acetone (7%), and a suite of other isoprene and terpene oxidation products (19%). A diversity of NMVOC emissions is responsible for PAN formation globally including isoprene (37%) and alkanes (14%). Anthropogenic sources are dominant in the extratropical Northern Hemisphere outside the growing season. Open fires appear to play little role except at high northern latitudes in spring, although results are very sensitive to plume chemistry and plume rise. Lightning NOx is the dominant contributor to the observed PAN maximum in the free troposphere over the South Atlantic.
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Li, Meng, Qiang Zhang, Bo Zheng, Dan Tong, Yu Lei, Fei Liu, Chaopeng Hong, et al. "Persistent growth of anthropogenic non-methane volatile organic compound (NMVOC) emissions in China during 1990–2017: drivers, speciation and ozone formation potential." Atmospheric Chemistry and Physics 19, no. 13 (July 12, 2019): 8897–913. http://dx.doi.org/10.5194/acp-19-8897-2019.
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Abstract. Non-methane volatile organic compounds (NMVOCs) are important ozone and secondary organic aerosol precursors and play important roles in tropospheric chemistry. In this work, we estimated the total and speciated NMVOC emissions from China's anthropogenic sources during 1990–2017 by using a bottom-up emission inventory framework and investigated the main drivers behind the trends. We found that anthropogenic NMVOC emissions in China have been increasing continuously since 1990 due to the dramatic growth in activity rates and absence of effective control measures. We estimated that anthropogenic NMVOC emissions in China increased from 9.76 Tg in 1990 to 28.5 Tg in 2017, mainly driven by the persistent growth from the industry sector and solvent use. Meanwhile, emissions from the residential and transportation sectors declined after 2005, partly offsetting the total emission increase. During 1990–2017, mass-based emissions of alkanes, alkenes, alkynes, aromatics, oxygenated volatile organic compounds (OVOCs) and other species increased by 274 %, 88 %, 4 %, 387 %, 91 % and 231 %, respectively. Following the growth in total NMVOC emissions, the corresponding ozone formation potential (OFP) increased from 38.2 Tg of O3 in 1990 to 99.7 Tg of O3 in 2017. We estimated that aromatics accounted for the largest share (43 %) of the total OFP, followed by alkenes (37 %) and OVOCs (10 %). Growth in China's NMVOC emissions was mainly driven by the transportation sector before 2000, while industry and solvent use dominated the emission growth during 2000–2010. Since 2010, although emissions from the industry sector and solvent use kept growing, strict control measures on transportation and fuel transition in residential stoves have successfully slowed down the increasing trend, especially after the implementation of China's clean air action since 2013. However, compared to large emission decreases in other major air pollutants in China (e.g., SO2, NOx and primary PM) during 2013–2017, the relatively flat trend in NMVOC emissions and OFP revealed the absence of effective control measures, which might have contributed to the increase in ozone during the same period. Given their high contributions to emissions and OFP, tailored control measures for solvent use and industrial sources should be developed, and multi-pollutant control strategies should be designed to mitigate both PM2.5 and ozone pollution simultaneously.
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SABI, Kokou, Hezouwe SONLA, Moursalou KORIKO, Kokou Eric GBEDJANGNI, and Bahema YAYA. "EVOLUTION OF POLLUTANTS EMISSIONIN RELATION TOROAD TRAFFIC IN THE CITY OF LOME (TOGO) FROM 2010 TO 2019." International Journal of Advanced Research 9, no. 12 (December 31, 2021): 51–57. http://dx.doi.org/10.21474/ijar01/13875.
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The automobile fleet in Togo has increased in the last decades with a patchwork of vehicles that are in majority older than ten (10) years. Until 2019, the car fleet in Togo was almost dependent upon petroleum products, and was consequentlya source of air pollutants emission. Lome is the capital city of Togo with the characteristic of having the highest road traffic volume that significantly impacts air quality. In accordance with the EMEP/EEA air pollutant emission inventory guide and the COPERT method, emissions of carbone monoxide (CO), nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOCs) and particulate matter (PM) are respectively estimated to: 2621.674 tCO 82.444 tNOx 558.778 tNMVOC and 7.241 tPM. In the time series 2010-2019, emissions of CO, NMVOCs and NOx fell overall with average yearly rates by respectively 83,0234 66,4888 and 0,8073 t/year whereas the PM emission rose(0,8208 t/year).
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Sarkar, Chinmoy, Vinayak Sinha, Baerbel Sinha, Arnico K. Panday, Maheswar Rupakheti, and Mark G. Lawrence. "Source apportionment of NMVOCs in the Kathmandu Valley during the SusKat-ABC international field campaign using positive matrix factorization." Atmospheric Chemistry and Physics 17, no. 13 (July 4, 2017): 8129–56. http://dx.doi.org/10.5194/acp-17-8129-2017.
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Abstract. A positive matrix factorization model (US EPA PMF version 5.0) was applied for the source apportionment of the dataset of 37 non-methane volatile organic compounds (NMVOCs) measured from 19 December 2012 to 30 January 2013 during the SusKat-ABC international air pollution measurement campaign using a proton-transfer-reaction time-of-flight mass spectrometer in the Kathmandu Valley. In all, eight source categories were identified with the PMF model using the new constrained model operation mode. Unresolved industrial emissions and traffic source factors were the major contributors to the total measured NMVOC mass loading (17.9 and 16.8 %, respectively) followed by mixed industrial emissions (14.0 %), while the remainder of the source was split approximately evenly between residential biofuel use and waste disposal (10.9 %), solvent evaporation (10.8 %), biomass co-fired brick kilns (10.4 %), biogenic emissions (10.0 %) and mixed daytime factor (9.2 %). Conditional probability function (CPF) analyses were performed to identify the physical locations associated with different sources. Source contributions to individual NMVOCs showed that biomass co-fired brick kilns significantly contribute to the elevated concentrations of several health relevant NMVOCs such as benzene. Despite the highly polluted conditions, biogenic emissions had the largest contribution (24.2 %) to the total daytime ozone production potential, even in winter, followed by solvent evaporation (20.2 %), traffic (15.0 %) and unresolved industrial emissions (14.3 %). Secondary organic aerosol (SOA) production had approximately equal contributions from biomass co-fired brick kilns (28.9 %) and traffic (28.2 %). Comparison of PMF results based on the in situ data versus REAS v2.1 and EDGAR v4.2 emission inventories showed that both the inventories underestimate the contribution of traffic and do not take the contribution of brick kilns into account. In addition, the REAS inventory overestimates the contribution of residential biofuel use and underestimates the contribution of solvent use and industrial sources in the Kathmandu Valley. The quantitative source apportionment of major NMVOC sources in the Kathmandu Valley based on this study will aid in improving hitherto largely un-validated bottom-up NMVOC emission inventories, enabling more focused mitigation measures and improved parameterizations in chemical transport models.
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Marques, Baptiste, Evangelia Kostenidou, Alvaro Martinez Valiente, Boris Vansevenant, Thibaud Sarica, Ludovic Fine, Brice Temime-Roussel, et al. "Detailed Speciation of Non-Methane Volatile Organic Compounds in Exhaust Emissions from Diesel and Gasoline Euro 5 Vehicles Using Online and Offline Measurements." Toxics 10, no. 4 (April 8, 2022): 184. http://dx.doi.org/10.3390/toxics10040184.
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The characterization of vehicle exhaust emissions of volatile organic compounds (VOCs) is essential to estimate their impact on the formation of secondary organic aerosol (SOA) and, more generally, air quality. This paper revises and updates non-methane volatile organic compounds (NMVOCs) tailpipe emissions of three Euro 5 vehicles during Artemis cold urban (CU) and motorway (MW) cycles. Positive matrix factorization (PMF) analysis is carried out for the first time on proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS) datasets of vehicular emission. Statistical analysis helped to associate the emitted VOCs to specific driving conditions, such as the start of the vehicles, the activation of the catalysts, or to specific engine combustion regimes. Merged PTR-ToF-MS and automated thermal desorption gas chromatography mass spectrometer (ATD-GC-MS) datasets provided an exhaustive description of the NMVOC emission factors (EFs) of the vehicles, thus helping to identify and quantify up to 147 individual compounds. In general, emissions during the CU cycle exceed those during the MW cycle. The gasoline direct injection (GDI) vehicle exhibits the highest EF during both CU and MW cycles (252 and 15 mg/km), followed by the port-fuel injection (PFI) vehicle (24 and 0.4 mg/km), and finally the diesel vehicle (15 and 3 mg/km). For all vehicles, emissions are dominated by unburnt fuel and incomplete combustion products. Diesel emissions are mostly represented by oxygenated compounds (65%) and aliphatic hydrocarbons (23%) up to C22, while GDI and PFI exhaust emissions are composed of monoaromatics (68%) and alkanes (15%). Intermediate volatility organic compounds (IVOCs) range from 2.7 to 13% of the emissions, comprising essentially linear alkanes for the diesel vehicle, while naphthalene accounts up to 42% of the IVOC fraction for the gasoline vehicles. This work demonstrates that PMF analysis of PTR-ToF-MS datasets and GC-MS analysis of vehicular emissions provide a revised and deep characterization of vehicular emissions to enrich current emission inventories.
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Fortems-Cheiney, A., F. Chevallier, I. Pison, P. Bousquet, M. Saunois, S. Szopa, C. Cressot, T. P. Kurosu, K. Chance, and A. Fried. "The formaldehyde budget as seen by a global-scale multi-constraint and multi-species inversion system." Atmospheric Chemistry and Physics Discussions 12, no. 3 (March 7, 2012): 6909–55. http://dx.doi.org/10.5194/acpd-12-6909-2012.
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Abstract. For the first time, carbon monoxide (CO) and formaldehyde (HCHO) satellite retrievals have been used together with methane (CH4) and methyl choloroform (CH3CCl3 or MCF) surface measurements in a complex inversion system. The CO and HCHO are, respectively from MOPITT and OMI instruments. The multi-species and multi-satellite dataset inversion is done for the 2005–2008 period. The robustness of our results is evaluated by comparing our posterior-modeled concentrations with several sets of independent measurements of atmospheric mixing ratios. The inversion results lead to significant changes from the prior to the posterior, in terms of magnitude and seasonality of the CO and CH4 surface fluxes and of the 3-D HCHO production by non-methane volatile organic compounds (NMVOCs). The latter is significantly decreased, indicating an overestimation of the biogenic NMVOCs emissions, such as isoprene, in the GEIA inventory. CO and CH4 surface emissions are increased by the inversion, from 1037 to 1409 Tg CO and from 489 to 528 TgCH4 on average for the 2005–2008 period. CH4 emissions present significant interannual variability and a joint CO–CH4 fluxes analysis reveals that tropical biomass burning probably played a role in the recent increase of atmospheric methane.
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Li, M., Q. Zhang, D. G. Streets, K. B. He, Y. F. Cheng, L. K. Emmons, H. Huo, et al. "Mapping Asian anthropogenic emissions of non-methane volatile organic compounds to multiple chemical mechanisms." Atmospheric Chemistry and Physics 14, no. 11 (June 5, 2014): 5617–38. http://dx.doi.org/10.5194/acp-14-5617-2014.
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Abstract. An accurate speciation mapping of non-methane volatile organic compounds (NMVOC) emissions has an important impact on the performance of chemical transport models (CTMs) in simulating ozone mixing ratios and secondary organic aerosols. Taking the INTEX-B Asian NMVOC emission inventory as the case, we developed an improved speciation framework to generate model-ready anthropogenic NMVOC emissions for various gas-phase chemical mechanisms commonly used in CTMs in this work, by using an explicit assignment approach and updated NMVOC profiles. NMVOC profiles were selected and aggregated from a wide range of new measurements and the SPECIATE database v.4.2. To reduce potential uncertainty from individual measurements, composite profiles were developed by grouping and averaging source profiles from the same category. The fractions of oxygenated volatile organic compounds (OVOC) were corrected during the compositing process for those profiles which used improper sampling and analyzing methods. Emissions of individual species were then lumped into species in different chemical mechanisms used in CTMs by applying mechanism-dependent species mapping tables, which overcomes the weakness of inaccurate mapping in previous studies. Emission estimates for individual NMVOC species differ between one and three orders of magnitude for some species when different sets of profiles are used, indicating that source profile is the most important source of uncertainties of individual species emissions. However, those differences are diminished in lumped species as a result of the lumping in the chemical mechanisms. Gridded emissions for eight chemical mechanisms at 30 min × 30 min resolution as well as the auxiliary data are available at http://mic.greenresource.cn/intex-b2006. The framework proposed in this work can be also used to develop speciated NMVOC emissions for other regions.
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Cao, Hansen, Tzung-May Fu, Lin Zhang, Daven K. Henze, Christopher Chan Miller, Christophe Lerot, Gonzalo González Abad, et al. "Adjoint inversion of Chinese non-methane volatile organic compound emissions using space-based observations of formaldehyde and glyoxal." Atmospheric Chemistry and Physics 18, no. 20 (October 19, 2018): 15017–46. http://dx.doi.org/10.5194/acp-18-15017-2018.
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Abstract. We used the GEOS-Chem model and its adjoint to quantify Chinese non-methane volatile organic compound (NMVOC) emissions for the year 2007, using the tropospheric column concentrations of formaldehyde and glyoxal observed by the Global Ozone Monitoring Experiment 2A (GOME-2A) instrument and the Ozone Monitoring Instrument (OMI) as quantitative constraints. We conducted a series of inversion experiments using different combinations of satellite observations to explore their impacts on the top-down emission estimates. Our top-down estimates for Chinese annual total NMVOC emissions were 30.7 to 49.5 (average 41.9) Tg yr−1, including 16.4 to 23.6 (average 20.2) Tg yr−1 from anthropogenic sources, 12.2 to 22.8 (average 19.2) Tg yr−1 from biogenic sources, and 2.08 to 3.13 (average 2.48) Tg yr−1 from biomass burning. In comparison, the a priori estimate for Chinese annual total NMVOC emissions was 38.3 Tg yr−1, including 18.8 Tg yr−1 from anthropogenic sources, 17.3 Tg yr−1 from biogenic sources, and 2.27 Tg yr−1 from biomass burning. The simultaneous use of glyoxal and formaldehyde observations helped distinguish the NMVOC species from different sources and was essential in constraining anthropogenic emissions. Our four inversion experiments consistently showed that the Chinese anthropogenic emissions of NMVOC precursors of glyoxal were larger than the a priori estimates. Our top-down estimates for Chinese annual emission of anthropogenic aromatics (benzene, toluene, and xylene) ranged from 5.5 to 7.9 Tg yr−1, 2 % to 46 % larger than the estimate of the a priori emission inventory (5.4 Tg yr−1). Three out of our four inversion experiments indicated that the seasonal variation in Chinese NMVOC emissions was significantly stronger than indicated in the a priori inventory. Model simulations driven by the average of our top-down NMVOC emission estimates (which had a stronger seasonal variation than the a priori) showed that surface afternoon ozone concentrations over eastern China increased by 1–8 ppb in June and decreased by 1–10 ppb in December relative to the simulations using the a priori emissions and were in better agreement with measurements. We concluded that the satellite observations of formaldehyde and glyoxal together provided quantitative constraints on the emissions and source types of NMVOCs over China and improved our understanding on regional chemistry.
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Li, M., Q. Zhang, D. G. Streets, K. B. He, Y. F. Cheng, L. K. Emmons, H. Huo, et al. "Mapping Asian anthropogenic emissions of non-methane volatile organic compounds to multiple chemical mechanisms." Atmospheric Chemistry and Physics Discussions 13, no. 12 (December 11, 2013): 32649–701. http://dx.doi.org/10.5194/acpd-13-32649-2013.
Full textAbstract:
Abstract. An accurate speciation mapping of non-methane volatile organic compounds (NMVOC) emissions has an important impact on the performance of chemical transport models (CTMs) in simulating ozone mixing ratios and secondary organic aerosols. In this work, we developed an improved speciation framework to generate model-ready anthropogenic Asian NMVOC emissions for various gas-phase chemical mechanisms commonly used in CTMs by using an explicit assignment approach and updated NMVOC profiles, based on the total NMVOC emissions in the INTEX-B Asian inventory for the year 2006. NMVOC profiles were selected and aggregated from a wide range of new measurements and the SPECIATE database. To reduce potential uncertainty from individual measurements, composite profiles were developed by grouping and averaging source profiles from the same category. The fractions of oxygenated volatile organic compounds (OVOC) were corrected during the compositing process for those profiles which used improper sampling and analyzing methods. Emissions of individual species were then lumped into species in different chemical mechanisms used in CTMs by applying mechanism-dependent species mapping tables, which overcomes the weakness of inaccurate mapping in previous studies. Gridded emissions for eight chemical mechanisms are developed at 30 min × 30 min resolution using various spatial proxies and are provided through the website: http://mic.greenresource.cn/intex-b2006. Emission estimates for individual NMVOC species differ between one and three orders of magnitude for some species when different sets of profiles are used, indicating that source profile is the most important source of uncertainties of individual species emissions. However, those differences are diminished in lumped species as a result of the lumping in the chemical mechanisms.
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Kormann, R., H. Fischer, M. de Reus, M. Lawrence, C. Brühl, R. von Kuhlmann, R. Holzinger, et al. "Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results." Atmospheric Chemistry and Physics Discussions 3, no. 2 (March 10, 2003): 1303–31. http://dx.doi.org/10.5194/acpd-3-1303-2003.
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Abstract. Formaldehyde (HCHO) is an important intermediate product in the photochemical degradation of methane and non-methane volatile organic compounds. In August 2001, airborne formaldehyde measurements based on the Hantzsch reaction technique were performed during the Mediterranean INtensive Oxidant Study, MINOS. The detection limit of the instrument was 42 pptv at a time resolution of 180 s (10–90%). The overall uncertainty of the HCHO measurements was 30% at a mixing ratio of 300 pptv. In the marine boundary layer over the eastern Mediterranean Sea average HCHO concentrations were of the order of 1500 pptv, in reasonable agreement with results from a three-dimensional global chemical transport model of the lower atmosphere including non-methane volatile organic compound (NMVOC) chemistry. Above the boundary layer HCHO mixing ratios decreased with increasing altitude to a minimum level of 250 pptv at about 7 km. At higher altitudes (above 7 km) HCHO levels showed a strong dependency on the airmass origin. In airmasses from the North Atlantic/North American area HCHO levels were of the order of 300 pptv, a factor of 6 higher than values predicted by the model. Even higher HCHO levels, increasing to values of the order of 600 pptv at 11 km altitude, were observed in easterlies transporting air affected by the Indian monsoon outflow towards the Mediterranean basin. Only a small part (~30 pptv) of the large discrepancy between the model results and the measurements of HCHO in the free troposphere could be explained by a strong underestimation of the upper tropospheric acetone concentration by up to a factor of ten by the 3D-model. Therefore, the measurement-model difference in the upper troposphere remains unresolved, while the observed dependency of HCHO on airmass origin might indicate that unknown, relatively long-lived NMVOCs &ndash or their reaction intermediates – associated with biomass burning are at least partially responsible for the observed discrepancies.
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Kormann, R., H. Fischer, M. de Reus, M. Lawrence, Ch Brühl, R. von Kuhlmann, R. Holzinger, et al. "Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results." Atmospheric Chemistry and Physics 3, no. 3 (June 23, 2003): 851–61. http://dx.doi.org/10.5194/acp-3-851-2003.
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Abstract. Formaldehyde (HCHO) is an important intermediate product in the photochemical degradation of methane and non-methane volatile organic compounds. In August 2001, airborne formaldehyde measurements based on the Hantzsch reaction technique were performed during the Mediterranean INtensive Oxidant Study, MINOS. The detection limit of the instrument was 42 pptv (1s) at a time resolution of 180 s (10-90%). The overall uncertainty of the HCHO measurements was 30% at a mixing ratio of 300 pptv. In the marine boundary layer over the eastern Mediterranean Sea average HCHO concentrations were of the order of 1500 pptv, in reasonable agreement with results from a three-dimensional global chemical transport model of the lower atmosphere including non-methane volatile organic compound (NMVOC) chemistry. Above the boundary layer HCHO mixing ratios decreased with increasing altitude to a minimum level of 250 pptv at about 7 km. At higher altitudes (above 7 km) HCHO levels showed a strong dependency on the airmass origin. In airmasses from the North Atlantic/North American area HCHO levels were of the order of 300 pptv, a factor of 6 higher than values predicted by the model. Even higher HCHO levels, increasing to values of the order of 600 pptv at 11 km altitude, were observed in easterlies transporting air affected by the Indian monsoon outflow towards the Mediterranean basin. Only a small part (~30 pptv) of the large discrepancy between the model results and the measurements of HCHO in the free troposphere could be explained by a strong underestimation of the upper tropospheric acetone concentration by up to a factor of ten by the 3D-model. Therefore, the measurement-model difference in the upper troposphere remains unresolved, while the observed dependency of HCHO on airmass origin might indicate that unknown, relatively long-lived NMVOCs - or their reaction intermediates - associated with biomass burning are at least partially responsible for the observed discrepancies.
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Feng, Leyang, Steven J. Smith, Caleb Braun, Monica Crippa, Matthew J. Gidden, Rachel Hoesly, Zbigniew Klimont, Margreet van Marle, Maarten van den Berg, and Guido R. van der Werf. "The generation of gridded emissions data for CMIP6." Geoscientific Model Development 13, no. 2 (February 6, 2020): 461–82. http://dx.doi.org/10.5194/gmd-13-461-2020.
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Abstract. Spatially distributed anthropogenic and open burning emissions are fundamental data needed by Earth system models. We describe the methods used for generating gridded datasets produced for use by the modeling community, particularly for the Coupled Model Intercomparison Project Phase 6. The development of three sets of gridded data for historical open burning, historical anthropogenic, and future scenarios was coordinated to produce consistent data over 1750–2100. Historical data up to 2014 were provided with annual resolution and future scenario data in 10-year intervals. Emissions are provided on a sectoral basis, along with additional files for speciated non-methane volatile organic compounds (NMVOCs). An automated framework was developed to produce these datasets to ensure that they are reproducible and facilitate future improvements. We discuss the methodologies used to produce these data along with limitations and potential for future work.
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Simpson, I. J., S. K. Akagi, B. Barletta, N. J. Blake, Y. Choi, G. S. Diskin, A. Fried, et al. "Boreal forest fire emissions in fresh Canadian smoke plumes: C<sub>1</sub>–C<sub>10</sub> volatile organic compounds (VOCs), CO<sub>2</sub>, CO, NO<sub>2</sub>, NO, HCN and CH<sub>3</sub>CN." Atmospheric Chemistry and Physics Discussions 11, no. 3 (March 22, 2011): 9515–66. http://dx.doi.org/10.5194/acpd-11-9515-2011.
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Abstract. Boreal regions comprise about 17% of the global land area, and they both affect and are influenced by climate change. To better understand boreal forest fire emissions and plume evolution, 947 whole air samples were collected aboard the NASA DC-8 research aircraft in summer 2008 as part of the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic compounds (NMVOCs) using gas chromatography. Together with simultaneous measurements of CO2, CO, CH4, CH2O, NO2, NO, HCN and CH3CN, these measurements represent the most comprehensive assessment of trace gas emissions from boreal forest fires to date. Based on 105 air samples collected in fresh Canadian smoke plumes, 57 of the 80 measured NMVOCs (including CH2O) were emitted from the fires, including 45 species that were quantified from boreal forest fires for the first time. After CO2, CO and CH4, the largest emission factors (EFs) for individual species were formaldehyde (2.1 ± 0.2 g kg−1), followed by methanol, NO2, HCN, ethene, α-pinene, β-pinene, ethane, benzene, propene, acetone and CH3CN. Globally, we estimate that boreal forest fires release 2.4 ± 0.6 Tg C yr−1 in the form of NMVOCs, with approximately 41% of the carbon released as C1–C2 NMVOCs and 21% as pinenes. These are the first reported field measurements of monoterpene emissions from boreal forest fires, and we speculate that the pinenes, which are relatively heavy molecules, were detected in the fire plumes as the result of distillation of stored terpenes as the vegetation is heated. Their inclusion in smoke chemistry models is expected to improve model predictions of secondary organic aerosol (SOA) formation. The fire-averaged EF of dichloromethane or CH2Cl2, (6.9 ± 8.6) ×10−4 g kg−1, was not significantly different from zero and supports recent findings that its global biomass burning source appears to have been overestimated. Similarly, we found no evidence for emissions of chloroform (CHCl3) or methyl chloroform (CH3CCl3) from boreal forest fires. The speciated hydrocarbon measurements presented here show the importance of carbon released by short-chain NMVOCs, the strong contribution of pinene emissions from boreal forest fires, and the wide range of compound classes in the most abundantly emitted NMVOCs, all of which can be used to improve biomass burning inventories in local/global models and reduce uncertainties in model estimates of trace gas emissions and their impact on the atmosphere.
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Simpson, I. J., S. K. Akagi, B. Barletta, N. J. Blake, Y. Choi, G. S. Diskin, A. Fried, et al. "Boreal forest fire emissions in fresh Canadian smoke plumes: C<sub>1</sub>-C<sub>10</sub> volatile organic compounds (VOCs), CO<sub>2</sub>, CO, NO<sub>2</sub>, NO, HCN and CH<sub>3</sub>CN." Atmospheric Chemistry and Physics 11, no. 13 (July 7, 2011): 6445–63. http://dx.doi.org/10.5194/acp-11-6445-2011.
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Abstract. Boreal regions comprise about 17 % of the global land area, and they both affect and are influenced by climate change. To better understand boreal forest fire emissions and plume evolution, 947 whole air samples were collected aboard the NASA DC-8 research aircraft in summer 2008 as part of the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic compounds (NMVOCs) using gas chromatography. Together with simultaneous measurements of CO2, CO, CH4, CH2O, NO2, NO, HCN and CH3CN, these measurements represent the most comprehensive assessment of trace gas emissions from boreal forest fires to date. Based on 105 air samples collected in fresh Canadian smoke plumes, 57 of the 80 measured NMVOCs (including CH2O) were emitted from the fires, including 45 species that were quantified from boreal forest fires for the first time. After CO2, CO and CH4, the largest emission factors (EFs) for individual species were formaldehyde (2.1 ± 0.2 g kg−1), followed by methanol, NO2, HCN, ethene, α-pinene, β-pinene, ethane, benzene, propene, acetone and CH3CN. Globally, we estimate that boreal forest fires release 2.4 ± 0.6 Tg C yr−1 in the form of NMVOCs, with approximately 41 % of the carbon released as C1-C2 NMVOCs and 21 % as pinenes. These are the first reported field measurements of monoterpene emissions from boreal forest fires, and we speculate that the pinenes, which are relatively heavy molecules, were detected in the fire plumes as the result of distillation of stored terpenes as the vegetation is heated. Their inclusion in smoke chemistry models is expected to improve model predictions of secondary organic aerosol (SOA) formation. The fire-averaged EF of dichloromethane or CH2Cl2, (6.9 ± 8.6) × 10−4 g kg−1, was not significantly different from zero and supports recent findings that its global biomass burning source appears to have been overestimated. Similarly, we found no evidence for emissions of chloroform (CHCl3) or methyl chloroform (CH3CCl3) from boreal forest fires. The speciated hydrocarbon measurements presented here show the importance of carbon released by short-chain NMVOCs, the strong contribution of pinene emissions from boreal forest fires, and the wide range of compound classes in the most abundantly emitted NMVOCs, all of which can be used to improve biomass burning inventories in local/global models and reduce uncertainties in model estimates of trace gas emissions and their impact on the atmosphere.
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Song, Xiaowei, and Yongpei Hao. "Vehicular Emission Inventory and Reduction Scenario Analysis in the Yangtze River Delta, China." International Journal of Environmental Research and Public Health 16, no. 23 (November 29, 2019): 4790. http://dx.doi.org/10.3390/ijerph16234790.
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Vehicular emissions have become an important source of air pollution, and their effective reduction control is essential to protect the environment. The aim of this study was to establish multi-year vehicular emission inventories for ten important air pollutants and to analyze emission control policy scenarios based on these inventories. The inter-annual emission analysis results showed that the ten pollutant emissions had different change trends during the past decade. The emissions of CO, non-methane volatile organic compounds (NMVOCS), NOx, PM2.5, PM10, and CH4 tended to increase first and then decrease, but the years in which they began to decrease varied; the emissions of CO2 and NH3 showed the most significant growth trends, increasing by 567% and 4004% in 2015 compared with 1999, while the emissions of N2O and SO2 showed a general increasing trend and decreased obviously in a certain year. Eight scenarios based on emission inventories were designed; compared with the BAU scenario, the ESV scenario was the most effective policy to control NOx, PM2.5, and CH4 emissions; the radical AER scenario could decrease the vehicular emissions of CO, NMVOCs, PM10, CO2, N2O, and NH3; and the RFS scenario could reduce vehicular SO2 emissions significantly by 93.64%.
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Vohra, Karn, Eloise A. Marais, Shannen Suckra, Louisa Kramer, William J. Bloss, Ravi Sahu, Abhishek Gaur, et al. "Long-term trends in air quality in major cities in the UK and India: a view from space." Atmospheric Chemistry and Physics 21, no. 8 (April 29, 2021): 6275–96. http://dx.doi.org/10.5194/acp-21-6275-2021.
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Abstract. Air quality networks in cities can be costly and inconsistent and typically monitor a few pollutants. Space-based instruments provide global coverage spanning more than a decade to determine trends in air quality, augmenting surface networks. Here we target cities in the UK (London and Birmingham) and India (Delhi and Kanpur) and use observations of nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI), ammonia (NH3) from the Infrared Atmospheric Sounding Interferometer (IASI), formaldehyde (HCHO) from OMI as a proxy for non-methane volatile organic compounds (NMVOCs), and aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) for PM2.5. We assess the skill of these products at reproducing monthly variability in surface concentrations of air pollutants where available. We find temporal consistency between column and surface NO2 in cities in the UK and India (R = 0.5–0.7) and NH3 at two of three rural sites in the UK (R = 0.5–0.7) but not between AOD and surface PM2.5 (R < 0.4). MODIS AOD is consistent with AERONET at sites in the UK and India (R ≥ 0.8) and reproduces a significant decline in surface PM2.5 in London (2.7 % a−1) and Birmingham (3.7 % a−1) since 2009. We derive long-term trends in the four cities for 2005–2018 from OMI and MODIS and for 2008–2018 from IASI. Trends of all pollutants are positive in Delhi, suggesting no air quality improvements there, despite the roll-out of controls on industrial and transport sectors. Kanpur, identified by the WHO as the most polluted city in the world in 2018, experiences a significant and substantial (3.1 % a−1) increase in PM2.5. The decline of NO2, NH3, and PM2.5 in London and Birmingham is likely due in large part to emissions controls on vehicles. Trends are significant only for NO2 and PM2.5. Reactive NMVOCs decline in Birmingham, but the trend is not significant. There is a recent (2012–2018) steep (> 9 % a−1) increase in reactive NMVOCs in London. The cause for this rapid increase is uncertain but may reflect the increased contribution of oxygenated volatile organic compounds (VOCs) from household products, the food and beverage industry, and domestic wood burning, with implications for the formation of ozone in a VOC-limited city.
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Johansson, Lasse, Erik Ytreberg, Jukka-Pekka Jalkanen, Erik Fridell, K. Martin Eriksson, Maria Lagerström, Ilja Maljutenko, Urmas Raudsepp, Vivian Fischer, and Eva Roth. "Model for leisure boat activities and emissions – implementation for the Baltic Sea." Ocean Science 16, no. 5 (October 2, 2020): 1143–63. http://dx.doi.org/10.5194/os-16-1143-2020.
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Abstract. The activities and emissions from leisure boats in the Baltic Sea have been modeled in a comprehensive approach for the first time, using a new simulation model leisure Boat Emissions and Activities siMulator (BEAM). The model utilizes survey data to characterize the national leisure boat fleets. Leisure boats have been categorized based on their size, use and engine specifications, and for these subcategories emission factors for NOx, PM2.5, CO, non-methane volatile organic compounds (NMVOCs), and releases of copper (Cu) and zinc (Zn) from antifouling paints have been estimated according to literature values. The modeling approach also considers the temporal and spatial distribution of leisure boat activities, which are applied to each simulated leisure boat separately. According to our results the CO and NMVOC emissions from leisure boats, as well as Cu and Zn released from antifouling paints, are significant when compared against the emissions originating from registered commercial shipping in the Baltic Sea. CO emissions equal 70 % of the registered shipping emissions and NMVOC emissions equal 160 % when compared against the modeled results in the Baltic Sea in 2014. Modeled NOx and PM2.5 from the leisure boats are less significant compared to the registered shipping emissions. The emissions from leisure boats are concentrated in the summer months of June, July and August and are released in the vicinity of inhabited coastal areas. Given the large emission estimates for leisure boats, this commonly overlooked source of emissions should be further investigated in greater detail.
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von Schneidemesser, E., M. Vieno, and P. S. Monks. "The changing oxidizing environment in London – trends in ozone precursors and their contribution to ozone production." Atmospheric Chemistry and Physics Discussions 14, no. 2 (January 16, 2014): 1287–316. http://dx.doi.org/10.5194/acpd-14-1287-2014.
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Abstract. Ground-level ozone is recognized to be a threat to human health (WHO, 2003), have a deleterious impact on vegetation (Fowler et al., 2009), is also an important greenhouse gas (IPCC, 2007) and key to the oxidative ability of the atmosphere (Monks et al., 2009). Owing to its harmful effect on health, much policy and mitigation effort has been put into reducing its precursors – the nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOCs). The non-linear chemistry of tropospheric ozone formation, dependent mainly on NOx and NMVOC concentrations in the atmosphere, makes controlling tropospheric ozone complex. Furthermore, the concentration of ozone at any given point is a complex superimposition of in-situ produced or destroyed ozone and transported ozone on the regional and hemispheric-scale. In order to effectively address ozone, a more detailed understanding of its origins is needed. Here we show that roughly half (5 μg m−3) of the observed increase in urban (London) ozone (10 μg m−3) in the UK from 1998 to 2008 is owing to factors of local origin, in particular, the change in NO : NO2 ratio, NMVOC : NOx balance, NMVOC speciation, and emission reductions (including NOx titration). In areas with previously higher large concentrations of nitrogen oxides, ozone that was previously suppressed by high concentrations of NO has now been "unmasked", as in London and other urban areas of the UK. The remaining half (approximately 5 μg m−3) of the observed ozone increase is attributed to non-local factors such as long-term transport of ozone, changes in background ozone, and meteorological variability. These results show that a two-pronged approach, local action and regional-to-hemispheric cooperation, is needed to reduce ozone and thereby population exposure, which is especially important for urban ozone.
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Kim, Hoegwon, Daisuke Watanabe, Shigeki Toriumi, and Enna Hirata. "Spatial Analysis of an Emission Inventory from Liquefied Natural Gas Fleet Based on Automatic Identification System Database." Sustainability 13, no. 3 (January 25, 2021): 1250. http://dx.doi.org/10.3390/su13031250.
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Many states are actively working toward regulating CO2 emissions from a wide range of industries. However, due to the international characteristic of shipping, the emissions from shipping have not yet been strictly controlled. Using Automatic Identification System (AIS) data acquired through satellites, this study estimates the emission inventory, such as, CO2, CH4, CH4, N2O, NOx, CO and non-methane volatile organic compounds (NMVOCs) around the world and bunker consumption from a liquified natural gas (LNG) fleet under the assumption that a LNG fleet uses LNG as fuel. Using position data calculated from an AIS database, we made comparisons regarding the LNG trade amount and bunker consumption of LNG fleet, as well as the total CO2 inventory and CO2 emissions from LNG fleet in the vicinity of the coasts of relevant countries. The result provides insights into (1) how the emissions and bunker consumption from LNG fleet is distributed, (2) which countries are taking relatively more advantages of LNG trade, and (3) which countries are suffering possible harmful effects.
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Striednig, Marcus, Martin Graus, Tilmann D. Märk, and Thomas G. Karl. "InnFLUX – an open-source code for conventional and disjunct eddy covariance analysis of trace gas measurements: an urban test case." Atmospheric Measurement Techniques 13, no. 3 (March 30, 2020): 1447–65. http://dx.doi.org/10.5194/amt-13-1447-2020.
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Abstract. We describe and test a new versatile software tool for processing eddy covariance and disjunct eddy covariance flux data. We present an evaluation based on urban non-methane volatile organic compound (NMVOC) measurements using a proton transfer reaction quadrupole interface time-of-flight mass spectrometer (PTR-QiTOF-MS) at the Innsbruck Atmospheric Observatory. The code is based on MATLAB® and can be easily configured to process high-frequency, low-frequency and disjunct data. It can be applied to a wide range of analytical setups for NMVOC and other trace gas measurements, and is tailored towards the application of noisy data, where lag time corrections become challenging. Several corrections and quality control routines are implemented to obtain the most reliable results. The software is open source, so it can be extended and adjusted to specific purposes. We demonstrate the capabilities of the code based on a large urban dataset collected in Innsbruck, Austria, where three-dimensional winds and ambient concentrations of NMVOCs and auxiliary trace gases were sampled with high temporal resolution above an urban canopy. Concomitant measurements of 12C and 13C isotopic NMVOC fluxes allow testing algorithms used for determination of flux limits of detection (LOD) and lag time analysis. We use the high-frequency NMVOC dataset to generate a set of disjunct data and compare these results with the true eddy covariance method. The presented analysis allows testing the theory of disjunct eddy covariance (DEC) in an urban environment. Our findings confirm that the disjunct eddy covariance method can be a reliable tool, even in complex urban environments when fast sensors are not available, but that the increase in random error impedes the ability to detect small fluxes due to higher flux LODs.
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Worden, Helen M., A. Anthony Bloom, John R. Worden, Zhe Jiang, Eloise A. Marais, Trissevgeni Stavrakou, Benjamin Gaubert, and Forrest Lacey. "New constraints on biogenic emissions using satellite-based estimates of carbon monoxide fluxes." Atmospheric Chemistry and Physics 19, no. 21 (November 8, 2019): 13569–79. http://dx.doi.org/10.5194/acp-19-13569-2019.
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Abstract. Biogenic non-methane volatile organic compounds (NMVOCs) emitted from vegetation are a primary source for the chemical production of carbon monoxide (CO) in the atmosphere, and these biogenic emissions account for about 18 % of the global CO burden. Partitioning CO fluxes to different source types in top-down inversion methods is challenging; typically a simple scaling of the posterior flux to prior flux values for fossil fuel, biogenic and biomass burning sources is used. Here we show top-down estimates of biogenic CO fluxes using a Bayesian inference approach, which explicitly accounts for both posterior and a priori CO flux uncertainties. This approach re-partitions CO fluxes following inversion of Measurements Of Pollution In The Troposphere (MOPITT) CO observations with the GEOS-Chem model, a global chemical transport model driven by assimilated meteorology from the NASA Goddard Earth Observing System (GEOS). We compare these results to the prior information for CO used to represent biogenic NMVOCs from GEOS-Chem, which uses the Model of Emissions of Gases and Aerosols from Nature (MEGAN) for biogenic emissions. We evaluate the a posteriori biogenic CO fluxes against top-down estimates of isoprene fluxes using Ozone Monitoring Instrument (OMI) formaldehyde observations. We find similar seasonality and spatial consistency in the posterior CO and top-down isoprene estimates globally. For the African savanna region, both top-down CO and isoprene seasonality vary significantly from the MEGAN a priori inventory. This method for estimating biogenic sources of CO will provide an independent constraint on modeled biogenic emissions and has the potential for diagnosing decadal-scale changes in emissions due to land-use change and climate variability.
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Bândă, N., M. Krol, M. van Weele, T. van Noije, P. Le Sager, and T. Röckmann. "Can we explain the observed methane variability after the Mount Pinatubo eruption?" Atmospheric Chemistry and Physics 16, no. 1 (January 18, 2016): 195–214. http://dx.doi.org/10.5194/acp-16-195-2016.
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Abstract. The CH4 growth rate in the atmosphere showed large variations after the Pinatubo eruption in June 1991. A decrease of more than 10 ppb yr−1 in the growth rate over the course of 1992 was reported, and a partial recovery in the following year. Although several reasons have been proposed to explain the evolution of CH4 after the eruption, their contributions to the observed variations are not yet resolved. CH4 is removed from the atmosphere by the reaction with tropospheric OH, which in turn is produced by O3 photolysis under UV radiation. The CH4 removal after the Pinatubo eruption might have been affected by changes in tropospheric UV levels due to the presence of stratospheric SO2 and sulfate aerosols, and due to enhanced ozone depletion on Pinatubo aerosols. The perturbed climate after the eruption also altered both sources and sinks of atmospheric CH4. Furthermore, CH4 concentrations were influenced by other factors of natural variability in that period, such as El Niño–Southern Oscillation (ENSO) and biomass burning events. Emissions of CO, NOX and non-methane volatile organic compounds (NMVOCs) also affected CH4 concentrations indirectly by influencing tropospheric OH levels.Potential drivers of CH4 variability are investigated using the TM5 global chemistry model. The contribution that each driver had to the global CH4 variability during the period 1990 to 1995 is quantified. We find that a decrease of 8–10 ppb yr−1 CH4 is explained by a combination of the above processes. However, the timing of the minimum growth rate is found 6&nash;9 months later than observed. The long-term decrease in CH4 growth rate over the period 1990 to 1995 is well captured and can be attributed to an increase in OH concentrations over this time period. Potential uncertainties in our modelled CH4 growth rate include emissions of CH4 from wetlands, biomass burning emissions of CH4 and other compounds, biogenic NMVOC and the sensitivity of OH to NMVOC emission changes. Two inventories are used for CH4 emissions from wetlands, ORCHIDEE and LPJ, to investigate the role of uncertainties in these emissions. Although the higher climate sensitivity of ORCHIDEE improves the simulated CH4 growth rate change after Pinatubo, none of the two inventories properly captures the observed CH4 variability in this period.
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Cai, H., and S. D. Xie. "Tempo-spatial variation of emission inventories of speciated volatile organic compounds from on-road vehicles in China." Atmospheric Chemistry and Physics Discussions 9, no. 3 (May 5, 2009): 11051–85. http://dx.doi.org/10.5194/acpd-9-11051-2009.
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Abstract. Emission inventories of sixty-nine speciated non-methane volatile organic compounds (NMVOC) from on-road vehicles in China were estimated for the period of 1980–2005, using seven NMVOC emission profiles, which were summarized based on local and international measurements from published literatures dealing with specific vehicle categories running under particular modes. Results show an exponential growth trend of China's historical emissions of alkanes, alkenes, alkines, aromatics and carbonyls during the period of 1980–2005, increasing from 63.9, 39.3, 6.9, 36.8 and 24.1 thousand tons, respectively, in 1980 to 2781.4, 1244.9, 178.5, 1350.7 and 403.3 thousand tons, respectively, in 2005, which coincided well with China's economic growth. Emission inventories of alkenes, aromatics and carbonyls were gridded at a high resolution of 40 km×40 km for air quality simulation and health risk evaluation, using the geographic information system (GIS) methodology. Spatial distribution of speciated NMVOC emissions shows a clear difference in emission densities between developed eastern and relatively underdeveloped western and inland China. Besides, the appearance and expansion of high-emission areas was another notable characteristic of spatial distribution of speciated NMVOC emissions during the period. Emission contributions of vehicle categories to speciated NMVOC groups showed annual variation, due to the variance in the provincial emissions and in the relative fractions of the seven emission profiles adopted at the provincial level. Highly reactive and toxic compounds accounted for high proportions of emissions of speciated NMVOC groups. The most abundant compounds were isopentane, pentane and butane from alkanes; ethene, propene, 2-methyl-2-butene and ethyne from alkenes and alkines; benzene, toluene, ethylbenzene, o-xylene, and m,p-xylene (BTEX) and 1,2,4-trimethylbenzene from aromatics and formaldehyde, acetaldehyde, benzaldehyde, acetone and acrolein from carbonyls.
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Cai, H., and S. D. Xie. "Tempo-spatial variation of emission inventories of speciated volatile organic compounds from on-road vehicles in China." Atmospheric Chemistry and Physics 9, no. 18 (September 22, 2009): 6983–7002. http://dx.doi.org/10.5194/acp-9-6983-2009.
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Abstract. Emission inventories of sixty-seven speciated non-methane volatile organic compounds (NMVOC) from on-road vehicles in China were estimated for the period of 1980–2005, using seven NMVOC emission profiles, which were summarized based on local and international measurements from published literatures dealing with specific vehicle categories running under particular modes. Results show an exponential growth trend of China's historical emissions of alkanes, alkenes, alkines, aromatics and carbonyls during the period of 1980–2005, increasing from 63.9, 39.3, 6.9, 36.8 and 24.1 thousand tons, respectively, in 1980 to 2778.2, 1244.5, 178.7, 1351.7 and 406.0 thousand tons, respectively, in 2005, which coincided well with China's economic growth. Emission inventories of alkenes, aromatics and carbonyls were gridded at a high resolution of 40 km×40 km for air quality simulation and health risk evaluation, using the geographic information system (GIS) methodology. Spatial distribution of speciated NMVOC emissions shows a clear difference in emission densities between developed eastern and relatively underdeveloped western and inland China. Besides, the appearance and expansion of high-emission areas was another notable characteristic of spatial distribution of speciated NMVOC emissions during the period. Emission contributions of vehicle categories to speciated NMVOC groups showed annual variation, due to the variance in the provincial emissions and in the relative fractions of the seven emission profiles adopted at the provincial level. Highly reactive and toxic compounds accounted for high proportions of emissions of speciated NMVOC groups. The most abundant compounds were isopentane, pentane and butane from alkanes; ethene, propene, 2-methyl-2-butene and ethyne from alkenes and alkines; benzene, toluene, ethylbenzene, o-xylene, and m,p-xylene (BTEX) and 1,2,4-trimethylbenzene from aromatics and formaldehyde, acetaldehyde, benzaldehyde and acetone from carbonyls.
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Zhao, Bin, Wenjing Wu, Shuxiao Wang, Jia Xing, Xing Chang, Kuo-Nan Liou, Jonathan H. Jiang, et al. "A modeling study of the nonlinear response of fine particles to air pollutant emissions in the Beijing–Tianjin–Hebei region." Atmospheric Chemistry and Physics 17, no. 19 (October 10, 2017): 12031–50. http://dx.doi.org/10.5194/acp-17-12031-2017.
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Abstract. The Beijing–Tianjin–Hebei (BTH) region has been suffering from the most severe fine-particle (PM2. 5) pollution in China, which causes serious health damage and economic loss. Quantifying the source contributions to PM2. 5 concentrations has been a challenging task because of the complicated nonlinear relationships between PM2. 5 concentrations and emissions of multiple pollutants from multiple spatial regions and economic sectors. In this study, we use the extended response surface modeling (ERSM) technique to investigate the nonlinear response of PM2. 5 concentrations to emissions of multiple pollutants from different regions and sectors over the BTH region, based on over 1000 simulations by a chemical transport model (CTM). The ERSM-predicted PM2. 5 concentrations agree well with independent CTM simulations, with correlation coefficients larger than 0.99 and mean normalized errors less than 1 %. Using the ERSM technique, we find that, among all air pollutants, primary inorganic PM2. 5 makes the largest contribution (24–36 %) to PM2. 5 concentrations. The contribution of primary inorganic PM2. 5 emissions is especially high in heavily polluted winter and is dominated by the industry as well as residential and commercial sectors, which should be prioritized in PM2. 5 control strategies. The total contributions of all precursors (nitrogen oxides, NOx; sulfur dioxides, SO2; ammonia, NH3; non-methane volatile organic compounds, NMVOCs; intermediate-volatility organic compounds, IVOCs; primary organic aerosol, POA) to PM2. 5 concentrations range between 31 and 48 %. Among these precursors, PM2. 5 concentrations are primarily sensitive to the emissions of NH3, NMVOC + IVOC, and POA. The sensitivities increase substantially for NH3 and NOx and decrease slightly for POA and NMVOC + IVOC with the increase in the emission reduction ratio, which illustrates the nonlinear relationships between precursor emissions and PM2. 5 concentrations. The contributions of primary inorganic PM2. 5 emissions to PM2. 5 concentrations are dominated by local emission sources, which account for over 75 % of the total primary inorganic PM2. 5 contributions. For precursors, however, emissions from other regions could play similar roles to local emission sources in the summer and over the northern part of BTH. The source contribution features for various types of heavy-pollution episodes are distinctly different from each other and from the monthly mean results, illustrating that control strategies should be differentiated based on the major contributing sources during different types of episodes.
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Fortems-Cheiney, A., F. Chevallier, I. Pison, P. Bousquet, M. Saunois, S. Szopa, C. Cressot, T. P. Kurosu, K. Chance, and A. Fried. "The formaldehyde budget as seen by a global-scale multi-constraint and multi-species inversion system." Atmospheric Chemistry and Physics 12, no. 15 (August 1, 2012): 6699–721. http://dx.doi.org/10.5194/acp-12-6699-2012.
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Abstract. For the first time, carbon monoxide (CO) and formaldehyde (HCHO) satellite retrievals are used together with methane (CH4) and methyl choloroform (CH3CCl3 or MCF) surface measurements in an advanced inversion system. The CO and HCHO are respectively from the MOPITT and OMI instruments. The multi-species and multi-satellite dataset inversion is done for the 2005–2010 period. The robustness of our results is evaluated by comparing our posterior-modeled concentrations with several sets of independent measurements of atmospheric mixing ratios. The inversion leads to significant changes from the prior to the posterior, in terms of magnitude and seasonality of the CO and CH4 surface fluxes and of the HCHO production by non-methane volatile organic compounds (NMVOC). The latter is significantly decreased, indicating an overestimation of the biogenic NMVOC emissions, such as isoprene, in the GEIA inventory. CO and CH4 surface emissions are increased by the inversion, from 1037 to 1394 TgCO and from 489 to 529 TgCH4 on average for the 2005–2010 period. CH4 emissions present significant interannual variability and a joint CO-CH4 fluxes analysis reveals that tropical biomass burning probably played a role in the recent increase of atmospheric methane.
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Zhang, Lei, Tianliang Zhao, Sunling Gong, Shaofei Kong, Lili Tang, Duanyang Liu, Yongwei Wang, et al. "Updated emission inventories of power plants in simulating air quality during haze periods over East China." Atmospheric Chemistry and Physics 18, no. 3 (February 13, 2018): 2065–79. http://dx.doi.org/10.5194/acp-18-2065-2018.
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Abstract. Air pollutant emissions play a determinant role in deteriorating air quality. However, an uncertainty in emission inventories is still the key problem for modeling air pollution. In this study, an updated emission inventory of coal-fired power plants (UEIPP) based on online monitoring data in Jiangsu Province of East China for the year of 2012 was implemented in the widely used Multi-resolution Emission Inventory for China (MEIC). By employing the Weather Research and Forecasting model with Chemistry (WRF-Chem), two simulation experiments were executed to assess the atmospheric environment change by using the original MEIC emission inventory and the MEIC inventory with the UEIPP. A synthetic analysis shows that power plant emissions of PM2.5, PM10, SO2, and NOx were lower, and CO, black carbon (BC), organic carbon (OC) and NMVOCs (non-methane volatile organic compounds) were higher in UEIPP relative to those in MEIC, reflecting a large discrepancy in the power plant emissions over East China. In accordance with the changes in UEIPP, the modeled concentrations were reduced for SO2 and NO2, and increased for most areas of primary OC, BC, and CO. Interestingly, when the UEIPP was used, the atmospheric oxidizing capacity significantly reinforced. This was reflected by increased oxidizing agents, e.g., O3 and OH, thus directly strengthening the chemical production from SO2 and NOx to sulfate and nitrate, respectively, which offset the reduction of primary PM2.5 emissions especially on haze days. This study indicates the importance of updating air pollutant emission inventories in simulating the complex atmospheric environment changes with implications on air quality and environmental changes.
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Zheng, Bo, Qiang Zhang, Guannan Geng, Cuihong Chen, Qinren Shi, Mengshi Cui, Yu Lei, and Kebin He. "Changes in China's anthropogenic emissions and air quality during the COVID-19 pandemic in 2020." Earth System Science Data 13, no. 6 (June 17, 2021): 2895–907. http://dx.doi.org/10.5194/essd-13-2895-2021.
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Abstract. The COVID-19 pandemic lockdowns led to a sharp drop in socio-economic activities in China in 2020, including reductions in fossil fuel use, industry productions, and traffic volumes. The short-term impacts of lockdowns on China's air quality have been measured and reported, however, the changes in anthropogenic emissions have not yet been assessed quantitatively, which hinders our understanding of the causes of the air quality changes during COVID-19. Here, for the first time, we report the anthropogenic air pollutant emissions from mainland China by using a bottom-up approach based on the near-real-time data in 2020 and use the estimated emissions to simulate air quality changes with a chemical transport model. The COVID-19 lockdown was estimated to have reduced China's anthropogenic emissions substantially between January and March in 2020, with the largest reductions in February. Emissions of SO2, NOx, CO, non-methane volatile organic compounds (NMVOCs), and primary PM2.5 were estimated to have decreased by 27 %, 36 %, 28 %, 31 %, and 24 %, respectively, in February 2020 compared to the same month in 2019. The reductions in anthropogenic emissions were dominated by the industry sector for SO2 and PM2.5 and were contributed to approximately equally by the industry and transportation sectors for NOx, CO, and NMVOCs. With the spread of coronavirus controlled, China's anthropogenic emissions rebounded in April and since then returned to the comparable levels of 2019 in the second half of 2020. The provinces in China have presented nearly synchronous decline and rebound in anthropogenic emissions, while Hubei and the provinces surrounding Beijing recovered more slowly due to the extension of lockdown measures. The ambient air pollution presented much lower concentrations during the first 3 months in 2020 than in 2019 while rapidly returning to comparable levels afterward, which have been reproduced by the air quality model simulation driven by our estimated emissions. China's monthly anthropogenic emissions in 2020 can be accessed from https://doi.org/10.6084/m9.figshare.c.5214920.v2 (Zheng et al., 2021) by species, month, sector, and province.
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Fadnavis, Suvarna, Chaitri Roy, Rajib Chattopadhyay, Christopher E. Sioris, Alexandru Rap, Rolf Müller, K. Ravi Kumar, and Raghavan Krishnan. "Transport of trace gases via eddy shedding from the Asian summer monsoon anticyclone and associated impacts on ozone heating rates." Atmospheric Chemistry and Physics 18, no. 15 (August 15, 2018): 11493–506. http://dx.doi.org/10.5194/acp-18-11493-2018.
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Abstract. The highly vibrant Asian summer monsoon (ASM) anticyclone plays an important role in efficient transport of Asian tropospheric air masses to the extratropical upper troposphere and lower stratosphere (UTLS). In this paper, we demonstrate long-range transport of Asian trace gases via eddy-shedding events using MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) satellite observations, ERA-Interim reanalysis data and the ECHAM5–HAMMOZ global chemistry-climate model. Model simulations and observations consistently show that Asian boundary layer trace gases are lifted to UTLS altitudes in the monsoon anticyclone and are further transported horizontally eastward and westward by eddies detached from the anticyclone. We present an event of eddy shedding during 1–8 July 2003 and discuss a 1995–2016 climatology of eddy-shedding events. Our analysis indicates that eddies detached from the anticyclone contribute to the transport of Asian trace gases away from the Asian region to the western Pacific (20–30∘ N, 120–150∘ E) and western Africa (20–30∘ N, 0–30∘ E). Over the last two decades, the estimated frequency of occurrence of eddy-shedding events is ∼68 % towards western Africa and ∼25 % towards the western Pacific. Model sensitivity experiments considering a 10 % reduction in Asian emissions of non-methane volatile organic compounds (NMVOCs) and nitrogen oxides (NOx) were performed with ECHAM5–HAMMOZ to understand the impact of Asian emissions on the UTLS. The model simulations show that transport of Asian emissions due to eddy shedding significantly affects the chemical composition of the upper troposphere (∼100–400 hPa) and lower stratosphere (∼100–80 hPa) over western Africa and the western Pacific. The 10 % reduction of NMVOCs and NOx Asian emissions leads to decreases in peroxyacetyl nitrate (PAN) (2 %–10 % near 200–80 hPa), ozone (1 %–4.5 % near ∼150 hPa) and ozone heating rates (0.001–0.004 K day−1 near 300–150 hPa) in the upper troposphere over western Africa and the western Pacific.
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Zhu, Jian, Shanshan Wang, Hongli Wang, Shengao Jing, Shengrong Lou, Alfonso Saiz-Lopez, and Bin Zhou. "Observationally constrained modeling of atmospheric oxidation capacity and photochemical reactivity in Shanghai, China." Atmospheric Chemistry and Physics 20, no. 3 (February 3, 2020): 1217–32. http://dx.doi.org/10.5194/acp-20-1217-2020.
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Abstract. An observation-based model coupled to the Master Chemical Mechanism (V3.3.1) and constrained by a full suite of observations was developed to study atmospheric oxidation capacity (AOC), OH reactivity, OH chain length and HOx (=OH+HO2) budget for three different ozone (O3) concentration levels in Shanghai, China. Five months of observations from 1 May to 30 September 2018 showed that the air quality level is lightly polluted or worse (Ambient Air Quality Index, AQI, of > 100) for 12 d, of which ozone is the primary pollutant for 10 d, indicating ozone pollution was the main air quality challenge in Shanghai during summer of 2018. The levels of ozone and its precursors, as well as meteorological parameters, revealed the significant differences among different ozone levels, indicating that the high level of precursors is the precondition of ozone pollution, and strong radiation is an essential driving force. By increasing the input JNO2 value by 40 %, the simulated O3 level increased by 30 %–40 % correspondingly under the same level of precursors. The simulation results show that AOC, dominated by reactions involving OH radicals during the daytime, has a positive correlation with ozone levels. The reactions with non-methane volatile organic compounds (NMVOCs; 30 %–36 %), carbon monoxide (CO; 26 %–31 %) and nitrogen dioxide (NO2; 21 %–29 %) dominated the OH reactivity under different ozone levels in Shanghai. Among the NMVOCs, alkenes and oxygenated VOCs (OVOCs) played a key role in OH reactivity, defined as the inverse of the OH lifetime. A longer OH chain length was found in clean conditions primarily due to low NO2 in the atmosphere. The high level of radical precursors (e.g., O3, HONO and OVOCs) promotes the production and cycling of HOx, and the daytime HOx primary source shifted from HONO photolysis in the morning to O3 photolysis in the afternoon. For the sinks of radicals, the reaction with NO2 dominated radical termination during the morning rush hour, while the reactions of radical–radical also contributed to the sinks of HOx in the afternoon. Furthermore, the top four species contributing to ozone formation potential (OFP) were HCHO, toluene, ethylene and m/p-xylene. The concentration ratio (∼23 %) of these four species to total NMVOCs is not proportional to their contribution (∼55 %) to OFP, implying that controlling key VOC species emission is more effective than limiting the total concentration of VOC in preventing and controlling ozone pollution.
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Stavrakou, T., J. F. Müller, I. De Smedt, M. Van Roozendael, G. R. van der Werf, L. Giglio, and A. Guenther. "Evaluating the performance of pyrogenic and biogenic emission inventories against one decade of space-based formaldehyde columns." Atmospheric Chemistry and Physics Discussions 8, no. 5 (September 10, 2008): 16981–7036. http://dx.doi.org/10.5194/acpd-8-16981-2008.
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Abstract. A new one-decade dataset of formaldehyde (HCHO) columns retrieved from GOME and SCIAMACHY is compared with HCHO columns simulated by an updated version of the IMAGES global chemical transport model. This model version includes an optimized chemical scheme with respect to HCHO production, where the short-term and final HCHO yields from pyrogenically emitted non-methane volatile organic compounds (NMVOCs) are estimated from the Master Chemical Mechanism (MCM) and an explicit speciation profile of pyrogenic emissions. The model is driven by the Global Fire Emissions Database (GFED) version 1 or 2 for biomass burning, whereas biogenic emissions are provided either by the Global Emissions Inventory Activity (GEIA), or by a newly developed inventory based on the Model of Emissions of Gases and Aerosols from Nature (MEGAN) algorithms driven by meteorological fields from the European Centre for Medium-Range Weather Forecasts (ECMWF). The comparisons focus on tropical ecosystems, North America and China, which experience strong biogenic and biomass burning NMVOC emissions reflected in the enhanced measured HCHO columns. These comparisons aim at testing the ability of the model to reproduce the observed features of the HCHO distribution on the global scale and at providing a first assessment of the performance of the current emission inventories. The high correlation coefficients (r>0.8) between the observed and simulated columns over most regions indicate a very good consistency between the model, the implemented inventories and the HCHO dataset. The use of the MEGAN-ECMWF inventory improves the model/data agreement in almost all regions, but biases persist over parts of Africa and the Northern Australia. Although neither GFED version is consistent with the data over all regions, a better match is achieved over Indonesia and Southern Africa when GFEDv2 is used, but GFEDv1 succeeds better in getting the correct seasonal patterns and intensities of the fire episodes over the Amazon basin, as reflected by the higher correlations calculated in this region.
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Smith, S. N., and S. F. Mueller. "Modeling natural emissions in the Community Multiscale Air Quality (CMAQ) Model–I: building an emissions data base." Atmospheric Chemistry and Physics 10, no. 10 (May 27, 2010): 4931–52. http://dx.doi.org/10.5194/acp-10-4931-2010.
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Abstract. A natural emissions inventory for the continental United States and surrounding territories is needed in order to use the US Environmental Protection Agency Community Multiscale Air Quality (CMAQ) Model for simulating natural air quality. The CMAQ air modeling system (including the Sparse Matrix Operator Kernel Emissions (SMOKE) emissions processing system) currently estimates non-methane volatile organic compound (NMVOC) emissions from biogenic sources, nitrogen oxide (NOx) emissions from soils, ammonia from animals, several types of particulate and reactive gas emissions from fires, as well as sea salt emissions. However, there are several emission categories that are not commonly treated by the standard CMAQ Model system. Most notable among these are nitrogen oxide emissions from lightning, reduced sulfur emissions from oceans, geothermal features and other continental sources, windblown dust particulate, and reactive chlorine gas emissions linked with sea salt chloride. A review of past emissions modeling work and existing global emissions data bases provides information and data necessary for preparing a more complete natural emissions data base for CMAQ applications. A model-ready natural emissions data base is developed to complement the anthropogenic emissions inventory used by the VISTAS Regional Planning Organization in its work analyzing regional haze based on the year 2002. This new data base covers a modeling domain that includes the continental United States plus large portions of Canada, Mexico and surrounding oceans. Comparing July 2002 source data reveals that natural emissions account for 16% of total gaseous sulfur (sulfur dioxide, dimethylsulfide and hydrogen sulfide), 44% of total NOx, 80% of reactive carbonaceous gases (NMVOCs and carbon monoxide), 28% of ammonia, 96% of total chlorine (hydrochloric acid, nitryl chloride and sea salt chloride), and 84% of fine particles (i.e., those smaller than 2.5 μm in size) released into the atmosphere. The seasonality and relative importance of the various natural emissions categories are described.
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Song, C. H., H. S. Kim, R. von Glasow, P. Brimblecombe, J. Kim, R. J. Park, and J. H. Woo. "Source identification and budget analysis on elevated levels of formaldehyde within ship plumes: a photochemical/dynamic model analysis." Atmospheric Chemistry and Physics Discussions 10, no. 6 (June 23, 2010): 15441–83. http://dx.doi.org/10.5194/acpd-10-15441-2010.
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Abstract. Elevated levels of formaldehyde (HCHO) along the ship corridors have been observed by satellite sensors, such as ESA/ERS-2 GOME (Global Ozone Monitoring Experiment), and were also predicted by global 3-D chemistry-transport models. In this study, three likely sources of the elevated HCHO levels were investigated to identify the detailed sources and examine the contributions of the sources (budget) of the elevated levels of HCHO in the ship corridors using a newly-developed ship-plume photochemical/dynamic model: (1) primary HCHO emission from ships; (2) secondary HCHO production via the atmospheric oxidation of Non-methane volatile organic compounds (NMVOCs) emitted from ships; and (3) atmospheric oxidation of CH4 within the ship plumes. From multiple ship-plume model simulations, CH4 oxidation by elevated levels of in-plume OH radicals was found to be the main factor responsible for the elevated levels of HCHO in the ship corridors. More than ~91% of the HCHO for the base ship plume case (ITCT 2K2 ship-plume case) is produced by this atmospheric chemical process, except in the areas close to the ship stacks where the main source of the elevated HCHO levels would be primary HCHO from the ships (due to the deactivation of CH4 oxidation from the depletion of in-plume OH radicals). Because of active CH4 oxidation (chemical destruction of CH4) by OH radicals, the instantaneous chemical lifetime of CH4 (τ CH4) decreased to ~0.45 yr inside the ship plume, which is in contrast to τ CH4 of ~1.1 yr in the background (up to ~41% decrease). A variety of likely ship-plume situations at three locations at different latitudes within the global ship corridors was also studied to determine the extent of the enhancements in the HCHOlevels in the marine boundary layer (MBL) influenced by ship emissions. It was found that the ship-plume HCHO levels could be 20.5–434.9 pptv higher than the background HCHO levels depending on the latitudinal locations of the ship plumes (i.e., intensity of solar radiation and temperature), MBL stability and NOx emission rates. On the other hand, NMVOC emissions from ships were not found to be a primary source of photochemical HCHOproduction inside ship plumes due to their rapid and individual dilution. However, the diluted NMVOCs would contribute to the HCHO productions in the background air. The greater impact of ship-plume photochemistry on the atmospheric MBL oxidation cycles, global climate, and marine eco-system in the global ship corridors are also discussed based on the results in this study.
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Yan, Liu, Bo Zheng, Guannan Geng, Chaopeng Hong, Dan Tong, and Qiang Zhang. "Evaporation process dominates vehicular NMVOC emissions in China with enlarged contribution from 1990 to 2016." Environmental Research Letters 16, no. 12 (November 30, 2021): 124036. http://dx.doi.org/10.1088/1748-9326/ac3872.
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Abstract Non-methane volatile organic compounds (NMVOC) are important precursors of ozone and secondary organic aerosols in PM2.5 (particulate matter with aerodynamic diameters smaller than 2.5 μm), both of which cause severe climate, ecosystem, and human health damages. As one of the major anthropogenic sources, onroad vehicles are subject to relatively large errors and uncertainties in the estimation of NMVOC emissions due to complicated methods and parameters involved and a lack of comprehensive evaluation of influencing factors. Here, based on our previous work with necessary improvement, we estimate China’s vehicular NMVOC emissions by county and by month during 1990–2016 with a consideration of meteorological influence on the spatial-temporal dynamics of emission factors. Our estimate suggests that vehicular NMVOC emissions in China have peaked around 2008 and then declined up to 2016 with an enlarged contribution of the evaporative process to vehicular NMVOC emissions. Vehicular NMVOC emissions have been dominated by the evaporative process at present. Meteorological factors alter spatial-temporal distributions of NMVOC emissions, especially evaporative emissions, which are enhanced in South China and in summer. Emissions and ozone formation potential of the major chemical groups (i.e. Alkenes, Aromatics, and Alkanes) also increase substantially due to meteorological influences. Our analysis suggests that mitigation strategies for vehicle pollutions should be designed based on a sophisticated emission inventory accounting for the meteorological impact on emission factors to correct the potential underestimation of NMVOC emissions, especially those from the evaporative process.